2 files changed, 10 insertions, 2 deletions
diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index 10fd1f57f6..d873cfec1b 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -199,10 +199,13 @@ void CXXNameMangler::mangle(const NamedDecl *D, llvm::StringRef Prefix) {
     return;
   }
 
-  // <mangled-name> ::= _Z <encoding>
+  // <mangled-name> ::= _Z [L] <encoding>
   //            ::= <data name>
   //            ::= <special-name>
   Out << Prefix;
+  if (D->getLinkage() == NamedDecl::InternalLinkage) // match gcc behavior
+    Out << 'L';
+
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
     mangleFunctionEncoding(FD);
   else
diff --git a/test/CodeGenCXX/mangle.cpp b/test/CodeGenCXX/mangle.cpp
index e8770dfec3..5947587eec 100644
--- a/test/CodeGenCXX/mangle.cpp
+++ b/test/CodeGenCXX/mangle.cpp
@@ -308,4 +308,9 @@ template class Alloc<char>;
 }
 
 // CHECK: define void @_Z1fU13block_pointerFiiiE
-void f(int (^)(int, int)) { }
-\ No newline at end of file
+void f(int (^)(int, int)) { }
+
+// PR5869
+// CHECK: define internal void @_ZL2f2v
+static void f2() {}
+void f3() { f2(); }